Power-control device for pneumatic-dispatch systems



June 1 ,1926, 1,586,634

J. G. MACLAREN ET AL POWER CONTROL DEVICE FORf PNEUMATIC DISPATCHSYSTEMS Filed Nov. 3. 1924 2 Sheets-Sheet 2 INVENTOR3 v Javfiesfiiifaczclv'ert, BY wrilli amep i'epverw z; $61M ATTORNEY Patented June1 1926. I 2 7V 1 I L umreo fiSTN-EES .3?P A*EENT QG'EEIQE.

"JAMESGI-MACBARENQOF MAMARONKJK, NEW YOBKQSAND WIIJDIAM- JHBPPERLEEOFBLOOMIIELDf-NEW ZTERSEYy-LSSIGNOBfi TO RHEEAAMSON GMMQAINYQOI SYKKUUFSE,"-"NEW YORK; A GRP0RATI0N 0I MiKSSACHUSETTS.

RIOWEBeOOMBOLiDEVICE iEOR ennumwlcmlsrnmcn SYSTEMS.

. pplicationkfiledmommber 3,,.1a24.saria1..m. 147,435.

1 This invention..re1ates;generelly..to pneu- .trating mhiodifiecl.formlofj.air.;c0ntr01ling imatic dispatch systemsaiidmmore particu-idevice. .Ja-rlytoineans foixconti'ollingi the .flowQofair If Referringtdtheldralwingsfor a more-dethnoughithe "carrier transmission vtubes; in.ac- .tiiiledljdeseription of the invention a double 5 'cordancewit-lithe dispatching. requirements. line system is"shownflirifltigureig i iofflthe k An: object of. .the invention is. to,proizide .drniw ing,...suchsys.tem .compiiisingxan outgoiimproyedmeans..formlimitingior srestrict1,,I l,g,'Lv inglme '5.hfwi-ngnn-inletoidispzitch .termithe fiowrof airthroiighthe.pneumatic.tubes ..11ial .1113 6.. located in. a central .recei'ving.,.and .of anexhziustdispatch system .wheiithetubes dispatch stationand a delivery terminal 7 l are. not being; :t rayersed by carriers. ateremote sendingstation. Thereturn line The iniiention.,includesmleans.asseciatedi 9.,is. connected.toltheuline 5.:ati'.the;:sef1ding cwitlutheinletendof a. tube: line fomauto- .statiomehd has; anii'nletopening' Slat .siid .-.matijcally shutting offaccessioflairflinto.the..stationehd a. deliizery openi ng..lQ.iidjacentline eizceptxwhen mcarrien occupies't-he dine to the inlet terminalGetithe .cential. station. ...-fo1-. transmission either toward .orfrom... a,..Tl1eiinco111ing.. line. 9. is, connected .througha.:centralistationwhere,.t11e..inlet.terminalv isgpipe' 111 withiL-heuderi 4 communicating .,l0cated..,. A featureof... the .\inventionis. a withany..suiteble,source,oiexhaustrsoflthat valveior-gatenormallytendiii to..,moveto a .Qthefeis eeonstantsu'ction intheheedertend- ,latched position .toiclose' the inlet-terminal ingvtd draw. airint'c thedoiibletube, line. at 0...and adapted tube:unlatchedyandnnoyedto Qthe inlet:terminel 6,-,in. .the .centralst ation open position. bythe engagement", therewith zilolliidjthro igli thegline 5- and. backthrough of :igcarrieiginserted in .thelinlet opening. .jthelin'e 9tothe, sourcelof exhaust. Another. featureof the invention isltheip'ro-'LLInorder. toobyiatethe .use'of ail-exhaustv.xiisioniozt advalvecontrolled inlet arrimged...i nm pu np l'ofrsiiiflicient apacity to.cause. a 25 to he uncovered by' the change i11.,-pressure f'u 1 flow ofair through all the pneumatic -conditionscausedbythe.openingof thecar-.-,dis pa.t ch tubes of. a system means'. is Iprorier.inlet;,gatenandiautoniaticelly to... move 'vided'rfor colltr ollilga-lldrestricting the'fiow i to e-closediposition Iwhen .subjeeted ,toithe '0f .air to. .aocofrd with What isneeded. to acpressurevariationsproducediili the sending tuzdlydispatcli'therequfredcarriersthrough sofltube by awmoving lcarrierandithe,increased:thefdispatchor.transittubes. ,ifiTheineans pvelocityQfflQWfif air indthe tube .imniedi-J, fo'1"...t.laus controlling theflowfof air thnqugh .ntely. following the; eXitfOfLthe carrier; fromLthe dispatch ,tubes-..iiicludes a ,.,spec.ial.valve the. delivery..endof. the tube. Q13. gate. member 12 for. eachfof. the. inlet. ,ter-

In.th'e drawings in "which preferredem minals 6 and 830i the doublelinetubesand a bodiment of the.iHVQiIiZiOIIdIHSwbQGII selectedcontrolling.devicelshowntait. 13 forshutting fouillustr'ation, thesupply ofair to the tube when a cer- Eigure .1 is a yiewinNeIticaI'.sectionjofthe liiie'r has completed itsijourney.fdispatclrendof atransmissionlineequipped The terminal 6 is formedatftlie lowerend with a. control: device embodying. the inven-,Otacasing'l? attached to theinletend'ofthe lio 1 transmission tube 5.,a1'1d.-is' illustrated.v as Figure, 2;is. a. view similar tol'Figure 1provided-"with e preferred" fromyof losure .showinge modifiedformjojfagate. fointh'e inlet comprising a get-e12 mounted upon aiislieftterminal. "15 turningin beari s inthe,.casi1 1g}l7 and E Fignre 3 isadetailviewsholwing a-; Vari-.iarrzynged to close egai11st an annularseat :ible sizedbaflle orlvane forming.part ofthe '21. A, latclr member20 is hinged at the invention; v.pioint 22 between Lugs projecting fromthe I Figure 4. is e-diugmmmetic Iview of. a vcasingHand is prdvidedwithacatch 24ifor 1 ..,doubleatubeldispatchlinewithiwhiclitheim.engegementwith' an eari 26 carried by'the Yentionmavbeused; ,under'side of the-gate 1'12. A;,spi*i11gi2& se-

1-.1Fig11re o. is. a .viewj.siiiiilanjtofEigure. 2. .cu-red to thecasingl'? teiidstomove th'elatch showing a further modifiedformr'ofcarrier? 20 into position for e ngagement.,ivithjthe 1hi-nletand .;.ear 126.1,The latchQOQisfproiiided with an flfigure 6 is aVertical.sectional.yieiiiillus-x inclined. cam face"30-for engegement byaengages a cam fin 32 projecting inwardly from a valve 34 normallyclosing a port in the side of the tube and opens the same to permitentrance of air into the tube atthe rear of the carrier which releasesthe suction in the line and thus brings about the release of thecontrolling device 13 to admit a supply of air to the tube 5 behind thetraveling carrier therein.

The gate 12 is swung to its closed position when the carrier has passedby means of a weight 42 carried by an arm 44 secured tothe shaft 15.

A spring 36 tends to restore the valve 34 to closed position, the returnmovement of the valve being retarded by a dash pot device shown at 38 towhich the valve 34 is connected through a link 40.

The modified gate mechanism illustrated in Figure 2 of the drawings,includes a gate 12 mounted on rock shaft 15 ournalled in the enlargementor casing 17 forming the dispatch terminal of the outgoing tube 5. Thegate 12 normally makes airtight contact with a gasket 19 resting on avalve seat 21 formed on the upper edge of the removable inlet section 6,a spring 49 tending to restore the gate to this position after beingopened.

In order normally to hold the gate 12 closed a latchis provided whichconsists of a link 23 whose free end 25 normally engages a spring catch27" carried by the casing 17 The link 23 is hinged at its inner end toone end of a link29 whose other end is pivoted to turn on shaft 15. Thelinks 23 and 29 thus form a toggle device having its two links or armsconnected by a contractile spring 31 which normally holds the arms inthe depressed position shown in Figure 2 with the joint at 45 adjacentto the inner surface of the gate and causes the extended end 25 of thelink or arm 23 to engage the catch 27 and thereby latch the gate in itsclosed position.

When the gate is closed, the toggle device also holds a valve member 33in engagement with a seat surrounding an orifice 35 formed in the gate12 thus preventing access of air through the inlet terminal 6 to thedispatch tube 5. The valve has substantially the same purpose as thevalve 34 of the modification shown in Figure 1 already referred to, thatis the opening of the valve 33, which takes place as a preliminary tothe opening of the carrier inlet gate 12, destroys the partial vacuum inthe casing and tube 5Va latch releasing arm 37 is pro vided which ishinged at 39 on the gate 12 and is connected through links 41 and 43 tothe hinge point 45 of the toggle links or arms 23 and 29. Insertion of acarrier into the inlet terminal 6 engages and elevates the latchoperating arm 37 and thereby forces the hinge point 45 of the togglearms to an elevated position which hits the valve 33 from its seat andwithdraws the extended end 25 of the arm 23 from its latching engagementwith the spring catch 29. The continued upward movement of the carrierunder the pressure of the hand of the operator lifts the gate 12 fromits seat 21 and thereby clears the passage for the entrance of thecarrier into the casing 17.

When the carrier has passed through the gate 12 the spring 49 becomeseffective to return the gate to its closed position. Meanwhile thetoggle arms 23 and 29 whose upward movement is limited by a stop member51, respond to the momentum of the closing movement of the gate to swingpast the mid position to again take the position shown in Figure 2 ofthe drawing, thus bringing the face end 25 of the arm 23 into latchingengagement with the catch 27 and at the same time forcing the valve 33to its seat to close the vent opening 35 in the gate 12.

The controlling device 13 which has already been reterred to isconnected through a conduit 53 with the casing 17 or 17 at the point 55above the position of the gate. The controlling device 13 includes ahollow cylindrical casing 57 in which there is mounted a fixed partition59 held in place by a suitable means such as ascrew 61. The partition 59is provided with a series of openings 63 through which air can pass fromthe space below the partition to the chamber formed in the upper part ofthe easing 57 above the partition member 59. Slidably mounted in thepartition 59 is a valve rod 65 which arries a sealing valve 67 normallyengaging the inner wall of the upper end of the casing 57 to prevent theflow of air from the casing into the tube 53. Carried on the valve rod65 and movable with it is a piston 69 which is fitted to the casing 57to slide therein beneath the partition 59. The lower extremity of thevalve rod 65 carries a. receptacle 71 in which may be placed material toconstitute a balancing weight for adjusting the control device for mosteffective operation.

The upper end of the rod 65 is provided with a two-part bafile or vane73 whose area etube 53-.is 'eliected-so; thatthevalve 67 underlithe-pull of the Weighted-receptacle" 71-i-s Withdrawn "from a -se aling engagement 1 withthe lower e'ndotthe tube 53iand drops-to a positionjust above partition-68. "Thisoperation permits air from'i nletport's75' Which-open through the side Wall of the casing near "its"upper-endto enter the casi-n-g 57andthe pipe 153, thus initiating theflow: foi -the car-Her *propelling current in -the transmission tube 5.

5 The eontinued'flowof air-through thecasing 57 into the-tube} 53 tendsto lift the piston 69 an d thus gradual lymoves the valve 67- toward itssealing-position against the end-of-the tube .53. This movement of thevalve 67-toward-its --sealii1gr position continues during the travel"ot= the carrier through the'tube 5. Upon the exitof-the carrier-tronthet-ube 5 at.theoutlettermi- 'nal an increased ru-sh' of airthrough-the tube 5' is momentarily produced and this rush-of'airacting-upon the bafiie -or vane '73 hits the rod 65. and completes theclosing of the "alve'67. Theaction ofzthelowveloc- -itya= air uponithe-bafile 73 -during-the movement ot the carrier through the -tube,' while1 less pronounced, assiststhe piston 69 to some extent atleastinproducing thegradhahupward movement of the valve-Bite its sea] ng-pos1t1on.-

The seatingof the --ralve 67' immediately .af-terthe exit-ofthe-carrier"from tlie'=delivery end=of the tube o' 'shuts bit the flowof I ai1'th1ougl1- the tube and thereby---prevents throughgan incomingtube 9 because the "idle COlHmIIfiOf air. A "Sllllllill:LOPQX'tItlOII'takes'place-" when the carrier 19 dispatched opening-of the inlet valve8 at the-outlying end of -the-c.incoming tube-bringsabout dropofpressurein the-inlet-tube Sand the 1 53 which -per1nits the weighted-receptacle'71 to niove'the "valve- '67 fronr'its sealing position. 1 The travelott' --connecting "tube the carrier throughthe-tube '9 will be accom-"-panied by the gradual rise'of thesealing =-Valve"'67 as *in the easealready described.

Theprovisionof thebaftleor vane 7 3 actuablebythe kinetic-energy of-theair passing operation of theeontrolling means is -there-- function-inthat a clean-cut and delinite by. insured.

l In or-der that l the sealing val ves!67 of the severaleonti'ol-devices 1350f -the "system-be m closed position wherrstartingtheexhauster,

"=85 withitheexhaust'header i utvany suitable point. t i Xspring. 87actsto project the latch rod; 7 9:- beneath the member. 77 and it herebyretainvthe-rodfifiandivalve 67 in its elevated position when the suctionin the tube 85-disappears upon. the shutting. down; of the ex ihaustdeviee.

i In Figure 5.otktheadrawing is shown a wnlOdi-fied folln OflCilEllQlinlet 6". which is provided. witlninwardly directed flanges -00 which.permit airto ipass into the casing 17 waroundnthe $il8SLOf1 the carrierduringtzthe operation:ofilpassingthecarrier through the gate. Thisconstruction avoidstheuse-"ot a valve su'clras is .shownnin Figures 1and 2 s tori-bringing? about aipreliminary disruption 1' ofthe;-.pa;rtial- Naouunr :conditions .to: cause ;.zthezinlet valve: 6.71in the con trot device 13 to movezto open :position.

TheWeight:carriedubyv the receptacle 71 -..can -be: varied to adjust.the :lift of the .valve I-JGZ'Z-to accord with the-length: of thetransit :gtllbt; and 1 thewolumer of: air required to. pass nthsroughtheicon-trol-.device. Also theeffec- 1stive area-i oththeubaflle7330-2111 be varied by 'adjustment-.::ot' its blades ainto greater orless-. overlapping engagement .to' produce the hidesired jefiect at theproper time.

1 Referring to 1' the modified 1 construction ishowir i11"- Fig'.;. theair: inlet controlling *dGVlCe 13 isiillustrated as. comprising the :21cylindrical casingiif'57 closed at its lower .-.end.-fati 100landsecured at itsup-per end to w'the lower end oftheconduit 53.

2 'Ehea-lower end slOO ofwthe casing is pro- Mided with a. -centralwopening defined by a .,.bushingf ."-I101.:-.Whieh guides the vertically.slidii1g.md l65 preferablyaprovided with an enlarged head 102 at itsupper end'toprevent thesirod. from escaping from the:casi11g.:A:.pistonl69 fits: snugly Within the eas- ==ingrf57iandinorinally rests uponthe head 1*02 4'of the rod 65". A piston rod 65is secured at-=its lower-end to'the piston69 andextends upwardly throughthe casing :a-nd into the lower end of the conduit'53. a Aha-theor-va-ne 73 preferably adjustable -.-in"area; is secured tothe upper endot-the ---r'od-":65 Fhe lower-end of the casing 57 through the tube 53*eflectsun "important-" i iurnish'ed with a'passage. 108 leading to the1 atmosphere, :the outer end of this pas- 1-sa-gebeing control-led by a,check valve 109 "adapted'gtopermit; free-escape of air from the lower-partiof .the. casing but to prevent 1-ejing r8SS"'0f air. ThelowerZendof the casing i-s -also furnished with a-passage 110 defines anorifice 106 through which air may i pass from the interior of the casing57 into the conduit 53. The upper part of the casing '7 is furnishedwith air inlet openings 107 spaced from the lower surface of the valveseat 104 a distance at least as great as the vertical thickness of thepiston 69 The lower end of the rod may be arranged to engage a retaininglatch 79 actuated in the same manner as the latch. 79 above described.

Normally the piston 69" occupies the upperpart of the casing 57 with itsvalve element 67 engaging the seat surface 104, the piston being held inthis position by the suction within the conduit 53. Then a carrier isplaced in the transmission tube the suction in the conduit drops and theweight of the piston 69 causes it to slide downwardly in the casing thusuncovering the orifice 106 and permitting a free flow of air to enterthrough the openings 10'? and orifice 106 into tube 53. The flowing airtends to evacuate the space above the piston so that the latter beginsslowly to rise, the rate of movement being regulated by the adjustmentof the needle valve 111. As the piston rises and passes the openings 107it gradually cuts off the air flow through the latter but as its lowersurface passes upwardly beyond said openings a free flow of air ispermitted to enter the space beneath the piston s0 that the piston isforcibly propelled into operative engagement with the seat 104 thuseffectively closing the orifice 106.

For proper operation the needle valve 111 is so set that the valve willnot close until the carrier has emerged from the transmission tube. Atthis instant there occurs a sudden increase in velocity in the airpassing through the conduit 53 and this rapidly moving air actsmechanically upon the baffle 73, causing it to exert a sudden liftingaction upon the valve, thereby accelerating its rate of closure so thatthe interval between delivery of the carrier and closure of the valve isreduced to a minimum.

While the form of mechanism here shown and described is admirablyadapted to fulfill the objects primarily stated, it is to be understoodthat it is not intended to conline the invention to the one embodimentherein disclosed, for it is susceptible of embodiment in various formsall coming within the scope of the claims which follow.

We claim: I

1. A pneumatic dispatch system comprising a transmission line, meanstending to create a carrier propelling air current in the line, adispatch terminal for the line, an inwardly opening gate normallyclosing said terminal, a normally closed controlling valve the openingof which initiates the flow of the carrier propelling air current in theline, said controlling valve opening automatically when the dispatchterminal gate is opened, and an air actuated battle spaced from butconnected to the Valve for closing the latter, said baflle being at alltimes disposed at the inner side of the valve orifice.

2. A pneumatic dispatch system having a transmission tube and a dispatchterminal therefor, said terminal being provided with a normally closedinwardly-opening carrier gate, a port for admitting air to the trans-.iission line, a normally closed closure member for the port, means foropening said closure when a carrier is inserted into the tube throughthe carrier gate, and a member disposed at all times at the inner sideof said port and responsive to the kinetic energy of flow of air throughthe admission port for moving the closure member toward port-closingposition.

A pneumatic dispatch system comprising a transmission tube having adispatch terminal, a normally closed inwardly-opening carrier gate insaid terminal, a latch for holding the gate closed, means engageable bya carrier entering the terminal for releasing the latch, a port foradmitting air to thetube, a normally closed controlling valve for theport, said valve opening automatically when a carrier is inserted in thetube through the carrier gate, and means including a baflie memberresponsible to the flow of air through the admission port for returningthe valve to port-closing position, said battle member being disposed atall times at the inner side of said port.

4. A pneumatic dispatch system comprising a central station, an outgoingtransmission tube leading from the central station and terminating at aremote sending station, an incoming transmission tube having aconnection at the sending station with the outgoing tube to permit airto flow from one tube to the other, exhaust means at the central stationhaving a connection with the incoming tube tending to produce acarrierpropelling flow of air through the tubes, an air inlet port atthe central station end of the outgoing tube, a closure for said portuorinally held in closed condition by suction, said valve openingautomatically when the suction is released, carrier actuatedmeanswforreleasing-the suction when a car-.- I18I"' 1S pl{ i0e(lvi111ieithertube, and a battle responsive to the velocity of-ifiow otair intothe.-tube throng-h;said-opened inlet port gradually'jto -move theclosure: member to closed position, said. battlebeing: disposed at=alltimes at the inner side of said port.

5. A pneumatic. dispatch system compris-- ing-atransit tubehavingadispatch terminal; an (inwardly opening,i:iiormal1y closed gate'in thetOI'llllIlBl,l11&llS tending-to cause airttoHow -through the tube-topropel car riers therethrough,,i antair-ad-niiss-ion port ZldJHCQIIt tOthe dispatch terminaha closure unenibeninornially closing the: port andarranged to open when a carrier is inserted through thegatez inithedispatch terminal, and a ibatllewspacedcfrom the closure mem berandwdisposedwatv t-he inner sideot' the port, said @baffie beingresponsive to the velocity .of --flow of -air. into the tube for ac,tuating the closure memberto close the air.- adm-ission-port;

6. A pneumatic dispatch system comprising a transitrtube, means tendingto cause an toflow through the tube to propel carllBI'Si therethrouglr,an air-adniiss1on port adj acentto itlle dispatching end-lot the tube, 1

a closure=member normally closing the port,

means: actuabler'by' a carrier insertedin the dispatchwend of the r tubefor causing the closure to 1' open randwadmiti a carrier propelling aircurrent to thetube,-'and' means 1H4 clud'ingma :pressurevactuatedwpiston and a baflte responsive to the rush-of air through said portfor-:iestoring -..tlie 1 closure to nor-- maliposition; e

7. A lpneumabicdispatch system liaving a transmissions.--linesands adispatch terminaltherefor, said terminal comprising ia casing: havingianwwent-rance passage; :a gate 5 within thewecasingunormally closedto i prevent cad mission rofi airi to the: line; a latclr for locking:.thc gate in closedsposition, toggle'ineans normally!retaiaiingwthelatch in locking; :PO:-'

sitionand; means; actuable' by engagement;

withrm caniiersthrust into tl1e-entrancewpa5= sage for breakingrgethe etoggle; -.thereby re-- tracbing fliewlatchnto iinoperative position.

89A" pneumatic: dispatch system having a transmission dine-ands adispatch terminals tliereforssa'id terminal: eoniprisinga casinghavingimr ientrnnce p assage;,-= an :annular seat within: cthear'casmgipcoaxialn: ,W1th 1 the pas-r sage, Jan .i nwa rdlyi swingingmgatenormally lockedzin iengagementwwith 'saidseat to-close the passagw said:gate havingaiaii a orifice theretlrrough-i a cover tor said orifice, andmeans iengageablewby: "a carrier thrust into theizentrance passageatouncover said orifice and to tunlook the: gate;

9. A4 pneumat-ic? dispatch system having a transmissioneline andvaterminal therefor, said:terminal comprising a casing having an entrancep assage va seat within the. casing,-

aninwardly swinging gate normally engag-.

ing said seattoclose thepassage;.said gate having anorificetlierethrough',:a toggle; de- 7 vice coniprisinga lever armpivoted coax ially with the gate aiida link pivot-ally con-- nected tothe tree end ot'the lever arm, the

link having a latch member at its end normally engagiiiga fixed membertohold the gate closed, a cover for the orifice connected to the free-endof said lever arm, and a member projecting.through/the orifice forengagement by. a carrier for breaking. the toggle. 1

10. A pneumatic dispatch system liavinga transmission line and aterminal-therefor, said terminal comprising a casing having an" entrancepassageztoradmission of-a carrier, a pivoted gate normally closing thepassage,

a toggle device at the inner-sideofthe'gatecomprising a lever armpivoted at one end coaxially with the gate, a link pivotally conr nectedto the free-end: ofthelever arm, a spring. tending to move the ointbetween the lever armandhnk toward the gate, a

latch normally engaginwa fixed part to lock,

the valvein closed position, and a member disposed in the=path of acarrier'thrust intothe entrance passage. and movable thereby to "movethejoint between thelink and lever arm away from the gate therebyretracting the-latch from said fixedpart and allowing the gate to open.

11. A pneumatic dispatch system having a transmission-line and adispatch terminal therefor having-a normally closed inlet passage and acontroller for determiningthe: initiation oi" carrier propelling airflow 1nthe line, said controller comprising a casing, a conduitconnecting thefcasing to thetransmission line, a valve =Wltll111 thecasing normally closing-- the entrance to the conduit, said valvenormally-being held closed by difli'erence in pressui'eat its oppositesides, buhOPGllllig upon a rise-in pressure iii the transittube, an airactuated balfle inthecona piston slidingmvithin the casing-ea valve"element movable with the piston and; nor- IHZLllyClOSIDg the entrance tothe conduit,

the casing having an inlet orifice interniedie ate itsends through.which air may pass to the conduit when the valve 15 open, and

means movable by the kinetic energyofairflowinginto the conduitandacting inconjunetion with the piston to close the valve;

13. A pneumatic dispatchvsystemhaving 'a cylindical casing, a conduitconnecting one end-of the casin with the transmission line, a valveelement normally closing the entrance to the conduit, a piston movingwith the valve element and having a sliding fit within the casing,difference in pressure upon opposite sides of the piston tending torestore the valve element, after it has been opened, to closed position,and means actuated by the kinetic energy of air flowing through the openvalve to assist the piston in closing the valve.

14. A pneumatic dispatch system having a transmission line in whichsuction is normally maintained and controlling means for opening saidline to admit a carrier propelling air current, said means comprising avertically disposed cylindrical casing, a conduit leading from the upperend'of the casing to the transmission line, the casing being providedwith a lateral'inlet opening adjacent to but below its upper end, avalve element normally closing the entrance to the conduit, said valveelement being normally held up in closed position by the suction in thetransmission line but dropping upon rise in pressure in the transmissionline, a piston moving with the valve element and having a sliding lit inthe cylinder, and a bafiie member disposed in the conduit and actuableby an air current flowing through the latter, said baffle beingconnected to the valve element.

15. A pneumatic dispatch system having a transmission line in whichsuction is normally maintained and controlling means for opening saidline to admit a carrier propelling air current said means comprising avertically disposed cylindrical casing, a conduit leading from the upperend of the casing to the transmission line, the casing being providedwith a lateral inlet opening adjacent to but below its upper end, thelower end of the cylinder being closed, a valve element in the cylindernormally closing the entrance to the conduit, a piston moving with thevalve element and having a close sliding lit in the cylinder, a baflleof less diameter than the conduit disposed within the latter, meansconnecting the battle to the valve, an orifice in the lower end of thecylinder below the piston, and a check valve substantially preventingentrance of air through said orifice but allowing its free escapetherefrom.

16. A pneumatic dispatch system having a transmission line in whichsuction is norinally maintained and controlling means for opening saidline to admit a carrier propelling air current, said means comprising avertically disposed cylindrical casing, a

conduit leading from the upper end of the casing to the transmissionline, the casing beng provided with a lateral inlet opening adjacent tobut below its upper end, a piston having a sliding fit in the casing,the upper surface of the piston constituting a valve and normallyclosing the entrance to the conduit, a bafile plate disposed within theconduit, a member connecting the baiile to the valve, a check valve inthe lower end of the casing permitting air freely to escape therefrombut substantially preventing its entrance, and an adjustable needlevalve admitting air in predetermined amount to enter the lower part ofthe casing below the piston.

17. A pneumatic dispatch system having a transmission line in whichsuction is normally maintained and controlling means for opening saidline to admit a carrier propelling air current, said means comprising avertically disposed cylindrical casing, a conduit leading from the upperend of the easing to the transmission line, the casing being providedwith a lateral inlet opening adjacent to but below its end, a valve inthe casing normally closing the entrance to the conduit but when openadmitting air freely to enter the conduit, means for closing the valve,means for retarding its closing movement and air actuated means disposedwithin the conduit and connected to the valve for lifting the lattertoward its seat.

18. A pneumatic dispatch system having a transmission line in whichsuction is nor mally maintained and controlling means for opening saidline to admit a carrier propelling air current, said means comprising avertically disposed cylindrical casing, a conduit leading from the upperend of the easing to the transmission line, the casing being providedwith a lateral inlet opening adjacent to but below its end, a valve inthe easing normally held up by the suction in the transmission line toclose the entrance to the conduit, and means operative upon cessation ofsuction in the transmission line to prevent the valve from openin 19. Apneumatic dispatch system having a transmission line in which suction.is normally maintained, and controlling means for opening said line toadmit a carrier propelling air current, said means comprising avertically disposed cylindrical casing, a conduit leading from the upperend of the easing to the transmission line, the casing being providedwith a lateral inlet opening adjacent to but below its upper end, avalve in the casing normally held in position by the suction in thetransmission line to close the entrance to the conduit, a stop operativeupon cessation of suction in the transmission line to prevent the valvefrom opening, and a suction actuated device normally holding the stop ininoperative position. 1

20. A pneumatic dispatch system having a transmission line in whichsuction is normally maintained and controlling means for opening saidline to admit a carrier propelling air current, said means comprising avertically disposed cylindrical casing, a conduit leading from the upperend of the easing to the transmission line, the casing being providedwith a lateral inlet opening adja cent to but below its upper end, avalve in the casing normally held in position by the suction in thetransmission line to close the entrance to the conduit, a springactuated stop positioned to prevent opening of the valve when suction inthe transmission line ceases, and a diaphragm connected to the stop andnormally holding it out of operative position in opposition to itsspring so long as working suction prevails in the transmission line.

21. A pneumatic dispatch system having air controlling means comprisingan elongate casing having a valve seat therein, an inlet orifice belowthe valve seat but above the bottom of the casing, a valve movable froma position where it engages the valve seat to a position where it isbelow the inlet orifice, a baflle disposed above the valve seat at alltimes, and means connecting the bafile to the valve.

22. A pneumatic dispatch system having air controlling means comprisingan elongate substantially cylindrical casing having an annular valveseat therein and an inlet orifice in its side wall intermediate thevalve seat and the bottom of the casing, a valve receivable within thelower part of the easing, a stem projecting upwardly from the valve, andmeans carried by the stem for lifting the valve up against its seat.

23. A pneumatic dispatch system having air controlling means comprisinga casing through which an air current flows, said casing being providedwith a valve seat, a lateral air inlet orifice below the valve seat, avalve movable upwardly past the inlet orilice into engagement with theseat, and means above the valve seat exposed to the air current passingthrough the valve seat and actuable by such current for lifting thevalve into the air current entering the inlet openmg.

24:. A pneumatic dispatch system having an air conduit and means forcontrolling the flow of air therethroughcomprising a valve and a seattherefor, the valve when fully open being disposed out of the path ofthe air current flowing in the conduit, and air actuated means disposedwithin such air current for moving the valve toward its seat and intothe path of the air current flowing toward and through thevalve seat.

Signed by us at Syracuse, N. Y., and Hartford, Conn, this 23rd and 24thday of October, 1924:.

JAMES e. MAGLAREN, WILLIAM J. HEPPERLE.

